Merge from origin/emacs-26

796c7f7 (origin/emacs-26) ; Fix last fix of 'mouse-drag-and-drop-region'
40d41dd (emacs-26) Fix Bug#28139
a5ec644 Fix Bug#29291
8b900e5 Fix Bug#2928
ff7bd84 Make 'mouse-drag-and-drop-region' work with 'mouse-autoselect...
0491de8 * etc/PROBLEMS: Remove fixed xterm-mouse-mode problems
caa39f4 Fix cookie handling (bug#29282)
93304e3 Improve documentation of Edebug and macros

diff --cc doc/lispref/edebug.texi
Simple merge

diff --cc etc/PROBLEMS
Simple merge

diff --cc lisp/url/url-cookie.el
Simple merge